How Worrisome Is This U.K. Virus Variant?
(Bloomberg Opinion) -- Sam Fazeli, a Bloomberg Opinion contributor who covers the pharmaceutical industry for Bloomberg Intelligence, answered questions about the emergence in the U.K. of a mutant variant of the coronavirus, which has prompted strict lockdown measures across England and led neighboring countries to put up trade and travel restrictions to protect against its spread. The conversation has been edited and condensed.
How unusual is this virus mutation?
SF: As far as viruses go, it’s not unusual to see mutations like this. They happen all the time, even within the same person. In fact, there have already been some 4,000 different documented mutations in the Sars-Cov-2 virus that causes Covid-19 as it has spread around the globe. Until now, none have been a real cause for concern. But the latest one that has been discovered in the U.K. is potentially worrisome, and I believe the government’s action in imposing severe lockdowns in London and southeastern England is warranted until more information is available.
The U.K. government says it took its action on lockdowns in part because the new variant may be as much as 70% more transmissible than original strains. What evidence is there of that?
SF: There is little hard data to prove that the new variant is transmitted more easily. The rapid rise in the number of cases in southeastern England may simply be because the virus was at the right place at the right time, just as was the case with a variant -- so-called D614G -- that was subsequently shown not to have better transmission but still became the dominant version of the virus in the U.S. and Europe. Also, one of the mutations related to this new variant has previously been shown to actually reduce transmission. So it’s just too early to know whether the spread is just luck or the result of a biological property of the virus. Without more information, though, it’s best to take these added precautions.
Does this variant cause a more severe form of Covid-19?
SF: Again, there are no hard data to suggest one way or another, but it’s very early days. Data on overall case counts relative to hospitalizations and mortality will in the next few weeks be able to provide preliminary clues. But definitive answers will need deeper study as there are many other confounding drivers of hospitalizations, such as the fact that infections are occurring in a colder climate, which is generally associated with weaker immune systems. Again, the mutation now dominant in the U.S. and Europe was thought to have 50% higher mortality, but that has turned out not to be the case.
Public Health England has said the there are increased infections in children because of this variant, and that may have been the cause of the spike in infections. What is that about?
In general, until now, children have been less susceptible to the virus and Covid-19 for a couple of reasons. One is that they don't have much of the so called ACE-2 receptor that adolescents and adults have; the virus has been found to adhere to this receptor as a way to infect cells, so having less of it reduces the chances of it getting in. The other is the power of children’s immune system, which diminishes with age. But if a virus variant is more effective in getting into human cells because it better binds to the ACE-2 receptor, then it increases the risk of infection even in children. This has repercussions for public health measures as to the way schools are operated and whether they are allowed to be open or not. It also increases the risk of seeing more pronounced disease in children.
What about vaccines? Is the immunity caused by the approved Pfizer Inc.-BioNTech SE and Moderna Inc. shots good enough to prevent disease from this variant?
SF: This is the big concern, but here’s what we know. This latest variant evolved with 17 mutations. Eight of these occurred in the part of the virus that’s targeted in the vaccines made by Pfizer-BioNTech and Moderna, as well as the shot in development by AstraZeneca Plc and the University of Oxford and many other companies. The working hypothesis of how this variant evolved is that it came from a chronically infected, immunocompromised patient who was treated with human convalescent plasma to protect against Covid-19. This gave the virus plenty of time to evolve in a way to allow it to grow despite the immune protection provided by the plasma. The problem is, that may also make it less sensitive to our current vaccines, given that the plasma therapy likely contained antibodies similar to those induced by the vaccines. In a press conference on Dec. 22, BioNTech's CEO said that the immune response to its vaccine works against regions of the virus — the so-called spike protein — that are not affected by the mutations in the variant. But there is still a risk that the mutations can change the “shape" of the spike protein such that the vaccine is less effective. Luckily, this is a relatively easy question to answer using blood from vaccinated individuals and laboratory experiments that look at how effectively this blood can kill the new variant. Also, given the high level of efficacy of the Pfizer-BioNTech and Moderna vaccines, a reduction from the 95% we have seen so far to even 60% or 70% would still mean a very good level of protection. Trials underway by AstraZeneca and Novavax Inc. include large numbers of subjects in Britain and can directly answer this question in the next few weeks. The U.K. rollout of Pfizer-BioNTech's vaccine will allow a similar analysis.
Still, if the variant is shown to be more resistant to vaccines, that would seem to be a problem. What can be done about that?
SF: It is critical that vaccine developers start working on this variant as soon as possible. Fortunately, new technologies from Pfizer-BioNTech, Moderna, AstraZeneca and Johnson & Johnson are quickly adaptable to mutations of the virus. AstraZeneca, in fact, has already started working on a new vaccine candidate against the variant. I also think that this may turn attention to the few companies — such as the Valneva SE and China’s Sinovac — that are developing Covid-19 vaccines using the killed virus itself. These, while potentially less effective than the modern vaccines, would cause a broader immune response.
What can be learned from the U.K.’s experience?
While I understand the government’s desire to support its economy, allowing indoor dining and the reopening of gyms in the past few months while cases were still at relatively high levels was misguided given the strong evidence that suggests the high risk of transmission in such settings. The U.K. should have followed the same path as France, which relaxed its rules but not to such an extent, keeping restaurants and bars closed. On the other hand, the U.K. has been a victim of its own success in that it does more genomic sequencing of the virus than almost all other countries. The pace and quantity of sequencing is what has allowed it to rapidly detect new variants of the virus. It is imperative that other countries do the same.
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